Eigrp Route Manipulation

[mazhar mahadik]

Hi Experts,

I have Scenario as attached, N below is the description

1) Eigrp 100 in on WAN cloud.

2) Eigrp 10 is on internal Network at Head office.

3) I am Redistributing Eigrp 100 in Eigrp 10 at R1 & R2

4) Redistribution metric on R1 is kept low than R2 , so Core selects R1 as best path.

5) when all links are UP. branch selects L1 link to reach HO.

6) when L1 goes down , branch selects L2 to reach HO. till this its all fine.

7) Now issue comes on return path, branch has neigborship with DR, n DR advertises branch subnets on DR link L3 to R1.

8) Since Redistribution cost on R1 is low, Core send return packet to R1, R1 sends to  DR & then DR sends it to branch,

9) While Bracnh communicates on L2 link.

How to acheive in this scenario, If L1 goes down core should send packet to R2 to reach branch.

Thanks in Advance.

[blau grana · Accepted solution]

Hello Mazhar

I assume that you set redistibution metric manualy on R1 and R2. If yes you cannot take to consideration local topology [if EIGRP route is learned from R1 or R2].

I think that best way to accomplish your goal will be to modify eigrp cost [eigrp parameters] on links between each router so during failure of any link, traffic will be rerouted toward desired path.

Then on R1 and R2 you do not have to set manualy metric, because during redistribution from EIGRP to EIGRP is used metric from sourced protocol [in your case eigrp 100] so EIGRP 10 will consider local EIGRP 100 area metric during DUAL algorithm.

Best Regards

Please rate helpful posts and close solved questions

[mazhar mahadik]

Hey Thanks blau grana

since when eigrp redistibuted into Eigrp RTR calculates cumulative metric of complete path,

i acheived my target by manupulating delay on Eigrp 100 links, & then core calculated complete path cost.

Thanks once again.

However it worked on my lab , but in real scenario wan links are formed by DMVPN running over L3mpls VPN.

but i guess it will work the same there as well, only difference is here i used physical links & there it will be DMVPN tunnel links.